Question

I need to create an arbitrarily large tarfile for testing but don’t want it to hit the disk.

What’s the easiest way to do this?

Answer 1

You can easily use python to generate such a tarfile:

mktar.py:

#!/usr/bin/python

import datetime
import sys
import tarfile

tar = tarfile.open(fileobj=sys.stdout, mode="w|")

info = tarfile.TarInfo(name="fizzbuzz.data")
info.mode = 0644
info.size = 1048576 * 16
info.mtime = int(datetime.datetime.now().strftime('%s'))

rand = open('/dev/urandom', 'r')

tar.addfile(info,rand)
tar.close()

---

michael@challenger:~$ ./mktar.py | tar tvf -
-rw-r--r-- 0/0        16777216 2012-08-02 13:39 fizzbuzz.data